President Bush has sought to bolster support for the war in Iraq by reminding U.S. citizens of the threat of terrorism and the need for peace in the Middle East.

Mr. Bush spoke Tuesday in Reno, Nevada, less than three weeks before a September 15 deadline for a crucial report to Congress on Iraq's military and political development.

The U.S. leader said that if violent extremists were allowed to flourish in the Middle East, unrest in the region could spread to other parts of the world. He said the U.S. war strategy in Iraq is working, despite frustrations over the pace at which the Iraqi government passes laws.

Mr. Bush said political change is coming about on the local level around Iraq, while U.S. troops have helped decrease the level of sectarian violence in the capital, Baghdad. He also said the policy is working at the international level, as the international community increasingly begins to understands the importance of a free Iraq.

Mr. Bush is under pressure from Democrats as well as members of his own party to begin withdrawing troops from Iraq.

Last week, an influential member of the Senate Armed Services committee, Republican John Warner, called on Mr. Bush to begin withdrawing troops before the end of this year.